June 3, 2013

In addition to the review of storm names for the season, it is also my custom to post a summary of forecasts of activity for the forthcoming hurricane season.

If one reads over my posts from past seasons, there will find some of my misgivings and caveats regarding these forecasts. The purpose of the annual posts isn’t necessarily to highlight the forecasts as an uber-important piece of data. It is merely a convenient one-stop summary of forecasts for the season and those of the recent years past.

The forecasts I track here come from the universities Colorado State, Florida State,North Carolina State as well as NOAA, the United Kingdom’s Meteorological office, and the consortium Tropical Storm Risk. Note that is not the authoritative collection of forecasts; as the years have gone by more and more organizations release forecasts. The forecasts I’ve opted to follow are for reasons of long track record and easily accessible forecast verification (in the cases of CSU, NOAA, and TSR), notable performance (NC State in 2006), and parochialism (FSU, though as we shall see, its performance has justified its presence here). While my compilation of forecasts from past season may give the impression that the UK forecast is quite new, that is not the case; for a number of seasons they issued a July-November forecast that was incompatible for comparison with the other forecasts.

While some forecasts provide more predictions than others (with variance in how the numbers are presented), I’ve reduced the forecasts to core numbers. That is, single numbers for predictions of named storms, hurricanes, major hurricanes, and Accumulated Cyclone Energy. Note that for organizations that issue multiple forecasts over the course of a year, I’ve used the “final” pre-season forecast. As a sort of performance baseline, I’ve also included the trailing average of the previous 5 seasons for the forecast parameters.

Without further rambling, here are the forecasts for 2008-2012, with links to NOAA’s season summary for each year.

One misconception that some people have of these forecasts is that “every season is forecast to be above-average”. As one can see from 2009, when the inhibiting effects of the El Niño were correctly anticipated, that is not the case. It is the case, however, that we have been in an ongoing multi-decadal period of increased hurricane activity. As such, forecasts of activity, as well as actual activity, will be above-average. Relatedly, some think that when these forecasts fail, it’s because they consistently over-predict the level of activity and serve to “hype” the storm threat. The forecasts from 2012 show that to not be the case; everyone’s forecast under-predicted the level activity.

Something that one may note when reviewing these numbers is that there isn’t that much spread in the forecast numbers, especially in the case of storm numbers. There is a bit more appreciable differences in the forecasts for Accunulated Cyclone Energy. In its four seasons of existence, the forecast from FSU has had the most accurate ACE forecast three times (though it’s one failure was rather bad; it was the highest forecast in 2011).

As we can see, the forecasts are in general unanimous in the expectation of an active season; the consenus number of storms forecast matches the average of the past five seasons exactly. Again, one sees a bit of spread in the ACE forecast, Colorado State’s forecast is a fair bit higher than everyone else’s (though if one examines the range of numbers in NOAA’s forecast, it will be found that their “high-end” number is higher, yet). There’s a suggestion in the ACE forecasts that storms on aggregate will be a little more intense and/or longer lived than those of past seasons.

In general, forecasters do not see any obvious inhibiting factors for the season to come. Of the forecasts that have explicit input parameters (vice being based off a wide-scoped computer model), nearly all parameters therein are tilting to the plus side for storm activity.

As I mentioned earlier, there are many other forecasts besides these; the Washington Post’s Capital Weather Blog had a post that linked to many of the ones that I did not include here.

June 1, 2013

Here we are on June 1st, at the start of another hurricane season in the Atlantic. Per my (admittedly not quite reliable) tradition, here is my review of the storm names for the season. Where did these unfamiliar names come from? What happened to some of the familiar ones? The answers come out below.

This year’s list of names is the sixth iteration of the list first used in 1983. This list has had the most changes (total of 12) along with the most names retired from the original group (10). Owing to the low number of storms in 1983, there are only two names that have been used in each iteration . Two of the names have never been used and three are on the list for the first time. The names (with links for years to images of the tracking chart for the storm and links for retired names to the Wikipedia entry):

Andrea – This spot on the list was originally filled by Alicia, which was replaced by Allison in 1989. Allison, of course is the only tropical storm to have its name retired. Andrea debuted in 2007 as a pre-season subtropical storm off the southeastern United States.

Barry – In 1983, a category 1 hurricane that had made landfall (as a tropical depression) at Melbourne, Florida before transversing the Gulf of Mexico to make landfall in northern Mexico. Tropical storm at sea in 1989. Hit Nova Scotia as a tropical storm in 1995. In 2001, made landfall on the Florida panhandle, again as a tropical storm. The 2007 edition also paid a visit to Florida as a tropical storm before traveling up the east coast in a post-tropical life.

Chantal – Category 1 hurricane at sea in 1983. The 1989 version struck Texas and was responsible for 13 fatalities (all due to drowning, the sad details can be read here). Tropical storm at sea in 1995 and in the Caribbean in 2001. The 2007 edition was a short-lived tropical storm that caused flooding in Newfoundland in its post-tropical life.

Erin – Category 2 hurricane at sea in 1989. Made landfall near Vero Beach, Florida as a category one hurricane , crossed the peninsula and made a second landfall near Fort Walton Beach as a category 2 in 1995. In 2001 it was an “interrupted-track” storm that eventually became a category three hurricane and passed just east of Bermuda and later Cape Race, Newfoundland (in its final hours as a tropical storm). The 2007 edition struck Texas as a tropical storm and the remnant low persisted into Oklahoma and strengthened briefly;the storm report has a paragraph on why the NHC did not consider it to be a tropical cyclone over Oklahoma despite its convective organization and relatively high winds.

Fernand – New for 2013. Replaces the name of the other category 5 hurricane of 2007, Felix.

Gabrielle – Category 4 hurricane at sea in 1989. Small tropical storm into northern Mexico in 1995. The 2001 edition caused a fair bit of flooding in Florida after making landfall on the west coast near Venice before re-intensifying to a category 1 hurricane in the Atlantic. In 2007, the name was attached to a short-lived tropical storm that affected the Outer Banks of North Carolina.

Humberto – Added to the list in 1995, replacing Hugo. The debut edition was a Category 2 hurricane as was the subsequent 2001 storm. In 2007, formed from the remnants of the same front that spawned Gabrielle. It went from tropical depression to hurricane in less than 19 hours and was rapidly strenghening prior to landfall at High Island, Texas.

Things can happen quickly in the Gulf.

Ingrid – Replaced Iris after the 2001 season. Inauspicious debut in 2007 as a weak and short-lived tropical storm.

February 20, 2013

In which the author offers some historical perspective on Ms. Patrick’s accomplishment as well as an explanation of some vagaries of The Great American Race

In 1994, an inexperienced driver named Loy Allen Jr. shocked the NASCAR world by becoming the first rookie to win pole position for the Daytona 500. Any race fan who remembers his name remembers it solely for that accomplishment as he never won a race.

In 2002, another rookie driver won the pole for the Daytona 500. His name was Jimmie Johnson and it is likely only fans of his and trivia fans who remember that particular accomplishment. That is because he went on to win six season championships and 60 races.

In 2013, Danica Patrick, in her first full season racing at the highest level of NASCAR, the Sprint Cup Series, became the first woman to win the pole position for the Daytona 500. One expects her career accomplishments in the Sprint Cup will lay somewhere between those of Jimmy Johnson and Loy Allen, but what about this race?

First, let us review what she has accomplished and what lies ahead for her.

As the premier race on the NASCAR schedule, the Daytona 500 is different from every other race with regards to how the field is set. Like any other race, there is a qualifying session. One by one, drivers take their car onto the track and get one chance at completing a lap of the race track as quickly as possible. The driver who is fastest wins the pole position **, the first starting position in the race. In general, the balance of the starting field for the race is filled on the basis of these qualifying laps in order of fastest to slowest. It was in such a qualifying session on Sunday that Danica Patrick earned the pole position for the Daytona 500. If this were any other race on the schedule, the qualifying session would be the sole story for who starts the race and in what order. But the Daytona 500 is unique.

For the Daytona 500, the qualifying session only fixes the first two positions, the pole position earned by Patrick and the position next to her, which was claimed by three-time D-500 winner Jeff Gordon. On Thursday, the qualifiers are divided into two groups (Danica Patrick and all odd-numbered qualifiers in one group, Jeff Gordon and all of the even numbered qualifiers in another) who will race in separate 150 mile events. The finishing order of these two events determines the next 30 drivers in the starting order behind Patrick and Gordon. Once those spots are filled, qualifying times from Sunday are again used to determine the balance of the field. As such, the third fastest driver in Sunday qualifying (Trevor Bayne) can find himself starting the race in 33rd if he has a poor showing on Thursday. Conversely, a driver that was slow in the qualifying session can dramatically improve his starting position with a strong result in his race on Thursday. For Danica Patrick, her finishing position in the race does not matter, but it is still important.

There are two ways Danica Patrick could have a bad day on Thursday. One involves events which erase the benefit of earning the pole position ***. If she is involved in an accident and her car is damaged beyond repair, she will have to race in the Daytona 500 in a backup car, which would force her to relinquish her first place starting position and send her to the back of the field. A major mechanical failure that necessitates an engine change carries the same consequence (.correction: A transmission change would warrant the penalty in any race. For the Daytona 500, an engine change is permitted after the Thursday race.)More subtlely, she could discover that while her car was set up ideally for running alone in the cool weather on Sunday, it is unsuited for racing in a pack of cars in warmer weather. That is, without changes, her car will be uncompetitive in the Daytona 500. As I’ll show shortly, success in qualifying does not necessarily translate to success in the big race.

While Thursday offers the only opportunity to experience race conditions, there are three more opportunities to test the car (or experience heart-breaking misfortune). There are two practice sessions on Friday and one on Saturday in which drivers can take their car onto the track and turn laps at their discretion. These sessions tend to be uneventful as a whole, but it is not unheard of for drivers to crash or have mechanical failures which send them to the back of the field for the start of the race on Sunday.

No driver starting in the pole position has won the Daytona 500 since 2000. Dale Jarret was on the pole that year and like the aforementioned Loy Allen, he was not in the lead when the first lap was completed. Unlike Loy Allen, he was in the lead for the most important lap, the final one, and 88 other ones as well. Since then, the average finishing of the pole-sitters has been 17th (Mildly interesting to note that the average finishing position of the three rookies to win the pole was slightly better, 16th). Some of this is due to the nature of the racing at the Daytona International Speedway. Cars will tend to run in one or two large lines (sometimes referred to as drafts), the lengths and arrangements of which change rapidly. A driver can be leading a line of cars one moment and suddenly find himself a number of positions behind when the draft breaks into a separate line and passes him by ***. The tendency of the cars to race very closely nose to tail in these lines makes the probability of a melee wreck involving a substantial number of cars very high; it is a rare Daytona 500 that does not have an incident referred to as “The Big One”; the largest crash of the race involving 10-20 cars with varying degrees of damage.

These features of Daytona racing can make it quite difficult for the inexperienced driver. Danica Patrick does have a couple of advantages over most rookie drivers of the past. One is that she is in top-tier machinery. She drives for a team that won the season championship in 2011 with her car’s engine coming from a team that won eight of the 16 championships before then. Secondly, the cars being raced this year are of a new design; drivers are still figuring out the particulars of their racing characteristics and how to best apply them to Daytona. Most lLessons learned by veterans in 2001 or 2011 will not apply.

Last year, driving an inferior car, Patrick was 29th in qualifying and finished 16th in her race on Thursday (caught in a crash near the end of the race). She started the 500 in 29th position and was caught in a wreck very early in the race and finished 38th. Depending on the strategy she employs in her race on Thursday, she may improve on last year’s result, but she also could run the race without incident and finish further back. ***** As only 43 cars compete in the 500, she is almost certain to improve on her finishing position in the big race. As history shows, most anything is possible and the pole position is no indicator of a strong finish. Barring her being victimized by a wreck not of her doing, I would expect her to finish in the front of the middle; 13th-25th position. 12th place would equal Janet Guthrie’s mark as the top finish by a female driver; anything higher would be a superlative effort.

** The term pole position comes from horse racing. While all forms of motorsport use it in the same fashion, NASCAR’s roots were closer to the origins of the term; many early stock car races took place on tracks also used for horse racing and the fastest qualifying car was placed first in line, next to “the pole”.

*** Only the first place starting position is forfeited; for the purpose of the record books, the fastest driver in qualifying is the pole-sitter even if he or she doesn’t actually start the race in first position. The only exception would be if the car or its fuel was found to be outside of regulations.

**** What I describe here is the general nature of NASCAR racing at Daytona for the better part of my lifetime. Changes in car aerodynamics as well as a repaving of the racing surface has caused variations over the years. It is not yet clear what sort of racing the newly designed cars will favor; the race on Thursday should bring some clarity.

*****Most veteran drivers starting their Thursday race in first would tend to follow a simple strategy: Run up front as long as possible, but if the lead is lost, fall to the back of the pack to ensure that you’re not caught in a wreck. The need for Danica Patrick to get more experience in race conditions may force her to “mix it up” and put her car more at risk than would sometimes be the norm.

December 12, 2012

One of the surprise highlights of the year in Jacksonville sporting events was a “friendly” soccer match between the mens national teams of the United States and Scotland. Played on a lovely Saturday evening in May, the match drew 44,438 fans, the most ever to attend an international friendly match in the state of Florida. This figure appeared even more impressive two weeks later when a World Cup qualifying match in Tampa attracted a mere 23,971 attendees *.

As one would expect, the success of the event immediately stirred activity to bring more soccer to Jacksonville. Your correspondent was hopeful that perhaps the Gold Medal winning women’s national team could be persuaded pay a visit to the River City for an international friendly. Last week though, Jacksonville mayor Alvin Brown (who had “more major sports in Jacksonville” as part of his campaign platform) hinted that the soccer to come would be of the domestic variety. This was confirmed yesterday when his office announced that the Philadelphia Union of Major League Soccer would play exhibition matches in Jacksonville in February for the next three years. The 2013 edition will serve as part of the Union’s visit to Florida to participate in the Walt Disney World Pro Soccer Classic, an exhibition tournament featuring five other MLS teams as well as ones from Orlando and Tampa.

This is nice. Give us more.

I attended and enjoyed the US-Scotland match. I am afraid there are a few reason why these matches to come will not be as successful:

The teams Philadelphia of course is one and the other will be an MLS team as well (presumably one of the others playing in Orlando). Neither will have the allure of the national team or an international professional team. Given that the nearest MLS team is DC United, it is understandable that the teams are not from the region. Still, the average person will find it to be a random selection of teams and will be unlikely to have a cheering interest in either of them.

The weather Those who were in Jacksonville during the week leading up to the Super Bowl will be quick to tell you that Jacksonville is not south Florida; warm pleasant weather is not a given. A night game will likely start with temperatures in the 50’s; cool weather by Florida standards, certainly cooler conditions than those for the match in May with the possibility existing that it could be cooler yet. Pleasant weather is not out of the question, however. Game day conditions for the aforementioned Super Bowl were fan-friendly.

The sports calendar Outside of The Player’s Championship golf tournament, May is a somewhat quiet time for sports in Jacksonville. Minor league baseball and arena football are in season, but neither provide an annual “classic” civic event. The area has a bit more going on in February. The forthcoming exhibition match will fall between the Grand-Am Endurance race in Daytona and the Daytona 500 (and is one day before the Daytona Shootout exhibition race). It comes two weeks after a first round Davis Cup tennis match between U.S. and Brazil. Most crushing to me, it falls on the same evening as the second basketball leg of the River City Rumble, the season long athletic competition between Jacksonville and the University of North Florida (I attended the game this year and intend to do so again in 2013). Granted, none of these events are of both large scale and in immediate proximity to the soccer match. It is almost certain though, that they will serve to reduce the number of people interested in attending another sporting fixture.

Taking these factors into consideration, I think an attendance of 30,000 is the best that can be hoped for… and that may be generous. It would be interesting to know how that lines up with what the city and Major League Soccer would consider to be a success.

* The weather was a factor in the reduced attendance in Tampa; it was anything but lovely.

October 28, 2012

In my youth I read any weather book I could get my hands on. One that I particularly treasured was called simply The Weather Book, which was written by the founding editor of the USA Today’s weather page.

Unfortunately, I do not have my copy on hand to quote from or refresh my memory on its contents. But as I recall, it had a page or two on the scenarios that meteorologists were most afraid of. One was a major hurricane hitting New Orleans and the other was a hurricane hitting the New York area.

The damages envisioned in the scenarios were so grave that some in the weather community always felt compelled, either in the name of safety or self-aggrandizement, to treat every storm that neared those locales as being The One.

To some extent, it was these false alarms that brought complacency to the Louisiana and Mississippi. Many people treated the nightmare scenario as a piece of fiction that would never really happen and paid the consequence. Others, who were a bit more in touch with reality, found themselves thinking “Wow,this is actually happening“. It was the former group of people that I was thinking of when, speaking to my father on the afternoon prior to Katrina’s landfall I said, “This is going to be so bad that people won’t believe it until they see it.”

That is not to say that meteorologists did not try to spread the word. A meteorologist at the local National Weather service office put his soul into his work

To restate what I wrote earlier, there are some who treat storms as their source of personal entertainment and do not hesitate to crank up the hype. There are others who take every unnecessary death in a storm as a personal failing. While the latter group contains cautious people (in the sense that they will advise some precautions that will prove to be unnecessary), they are so cautious that they do not pour their soul into their work when it is not warranted. Robert Ricks, the author of the Katrina bulletin, stopped and re-read his bulletin, to make sure that he didn’t include any statement that was unwarranted. I suspect that Gary Szatkowski exercised the same amount of caution when he drafted his “personal plea”.
Three possible sources of complacency, which I will briefly address:

“They don’t really know if the storm will hit us”

“Given how many of the New York false alarms happened in the not so recent past, this sense is probably greater among older people than is generally appreciated. Their memories are sharper of the days when hurricanes were totally unpredictable beasts and forecasts weren’t to be trusted beyond a day out. Those days are long past. While it is true that forecasters cannot predict the exact landfall point two days out, the science has progressed such that they will not miss by much. Hence the NWS forecaster’s statement that “The focus of efforts should be on when Sandy hits our region, not if Sandy hits our region.”

“They said Irene was going to be the horrible one and it wasn’t”

While this storm seems similar to Irene in the headline numbers that the public is most familiar with (maximum winds, Saffir-Simpson category) , it is a very different storm. At the comparable position point in Irene’s life, the extent of hurricane force winds was 85 miles with tropical storm force winds extending 285 miles away from the center. Right now hurricane winds extend up to 175 miles away from the center of Sandy and tropical storm winds reach out a staggering 520 miles. This has tremendous implications for storm surge. The most recent analysis of Sandy’s winds from NOAA’s Hurricane Research Division reveals an extremely high potential for damage from storm surge, higher than any hurricane observed in the 1969-2005 time-frame (See Dr. Masters’ commentary Sandy’s storm surge a huge threat for more on this.) As Dr Masters notes, Irene was a close call. The storm surge from Sandy will be worse.

Allow me to pick a random data point from a location with which I am personally familiar: Bridges in Chesapeake, Virginia have been closed due to flooding caused by Sandy. This happened during Irene as well. Irene, however, passed immediately to the south of Chesapeake. Sandy is over 300 miles away.

“It just doesn’t seem that bad. It’s a category one hurricane, and a border-line one at that.”

Of the three points listed here, it’s the one I have the most sympathy for. For years now forecasters have known that they needed to either tweak the Saffir-Simpson scale or bring additional measures of a storm’s potential for destruction into the public eye. For various reasons that has not happened. This may very well be that brings in new measures. I fear that due to the public’s unfamiliarity with the Hurricane Research Divsion’s product they think it’s something not quite real that is being used as a tool of the hypesters. That is not the case. It is a very real warning.

Complicating matters is the technical matter of Sandy’s nature when the storm makes landfall. Resulting from that is a “controversy” over whether the National Hurricane Center should be issuing warnings for the northeast. The NHC issued a two page release on the matter. I don’t have anything to say on the matter. This is not the time to be arguing.

It is a time for meteorologists to sound the alarm and for residents in and near the path of Sandy to prepare for the worst. While, by terminology, Sandy will not be the first major hurricane to hit the United States since 2005, it will be major in the conventional sense of the word. As far as the New York City nightmare scenario goes, Sandy is The Big One.

June 3, 2012

Having reviewed the past performance of these forecasts in my previous post, it is now time to look at the forecasts for the current hurricane season.

The official start of the season comes with two named storms, Alberto and Beryl already having come and gone. As most forecasts are explicitly June 1 – November 30, those storms do not count against these forecasts as listed here (I’ve adjusted the number of named storms forecast by Colorado State downward by two, per their note) .
Is this pre-season activity significant when considering activity for the rest of the season? The Colorado State forecast notes

Pre-1 June activity has very little bearing on the rest of the hurricane season. The only two seasons on record with two named storms prior to 1 June were 1887 and 1908. While 1887 was a very active season, 1908 had average levels of activity. The last season with a U.S. landfall prior to 1 June was 1976, which was a relatively quiet season.

Also note that by this time in the 2007 season, there already were two names in the books. While that season finished with a respectable number of named storms (15), aggregate activity as measured by ACE (72 units) was below the long term average.

Sorry Beryl, you don’t count

Here is a summary of the forecasts from the six organizations I track. It lists the number of named storms, hurricanes, and major hurricanes forecast along with the predicted amount of Accumulated Cyclone Energy. The consensus forecast (calculated as a simple average of unrounded numbers from all forecasts) is for twelve named storms, six hurricanes, and 97 units of ACE. This forecast is slightly below the average of the past five seasons and roughly in line with the 1981-2010 average.

I’ll know briefly review each forecast in alphabetical order. Note that a few forecasts contain much more information than that’s what displayed here. I’ll mention it as necessary so that those interested may delve into the forecasts on their own; I won’t be covering everything in detail, however.

The grandfather of these seasonal forecasts is that issued by researchers affiliated with Colorado State University; Dr. William Gray issued his first forecast in 1984 and since 2005 Phillip Klotzbach has been listed as the primary author with Dr. Gray second. The forecast is statistically driven, though, for the current scheme, one input comes from a computer model. The methodology has been alternatively tweaked and replaced in whole over the years; the current scheme is new to 2012.

The Colorado State 2012 hurricane season forecast calls for 11 named storms to form after June 1 with 5 becoming hurricanes and 2 of those being major hurricanes and a combined 80 units of ACE. The forecast discusses mixed signals as to whether a full blown El Niño event will develop or neutral conditions will prevail along with near-normal to cooler than normal Sea Surface Temperatures (SSTs) in the Atlantic as being factors in their forecast. Regarding the latter issue, the forecast states “Overall, the Atlantic is experiencing more marginal conditions this year than in many previous years during the active era that has been experienced since 1995.” It is worth noting that their forecast for Accumulated Cyclone Energy would be the lowest forecast since 1994 *** and is the lowest of the six forecasts tracked here.

The forecast also contains landfall forecast probabilities along with a lengthy discussion of whether rising CO2 levels in the atmosphere have contributed to the increase in major hurrricanes in the Atlantic since 1995.

Since 2009, a team at Florida State University lead by Tim LaRow has been issuing forecasts. The forecasts are generated using computer model simulations that were originally described in the paper Atlantic Basin Hurricane Simulations. Due to apparent limitations in model resolution, the model does not generate hurricanes that are at or above the major hurricane threshold, hence the lack of a forecast number of major hurricanes.

Not Tim LaRow

The FSU 2012 hurricane season forecast calls for 13 tropical storms and 7 hurricanes. The forecast for ACE is the highest: 122 units. It is worth remembering that FSU’s ACE forecast was also the highest and therefore ended up being the most wrong. This year, however, the FSU forecast is alone at the high end; last year the CSU forecast was nearly identical to that of FSU.

Since 2005, professor Lian Xie of North Carolina State University has been the lead for releasing forecasts from his institution. His statistical approach garnered significant attention in 2006 when it correctly forecast a quiet season when others suggested more activity.

The NC State 2012 hurricane season forecast gives a range of numbers, which average to 9 named storms, 6 hurricanes, and 2 major hurricanes. The forecast also predicts storm numbers for the Gulf of Mexico and gives some landfall probabilities, though it is not nearly as extensive as the predictions from Colorado State.

Since 1999, the Climate Prediction Center of NOAA has been issuing outlooks, in collaboration with the National Hurricane Center and the Hurricane Research Division. The basic factors for the forecast are fairly unchanged; the state of El Niño and SSTs in the Atlantic are the two primary considerations. A variety of computer models are utilized to predict those two factors.

NOAA’s 2012 Hurricane Season Outlook gives a range of numbers, which average to 12 named storms, 6 hurricanes, and 2 major hurricanes. Like the CSU forecast, it discusses the spread in El Niño forecasts as a source of uncertainty. It also reviews the near-normal to below average SSTs in the Atlantic.

The Tropical Storm Risk consortium was borne out of a UK government sponsored project named TSUNAMI. The first forecast was released under the latter name for the 1999 hurricane season with Professor Mark Saunders as the lead author. It utilizes a statistical approach considering two factors: Forecast SSTs in the Mean Development Region of the Atlantic Ocean (10°-20°N — 20°-60°W, the classic breeding ground for Atlantic tropical cyclones) and forecast low level trade winds over the Atlantic and Carribean.

Tropical Storm Risk’s 2012 Atlantic hurricane forecast predicts 13 named storms, 6 hurricanes, and three major hurricanes. Of the two values used in the forecast, the one for trade winds suggest a slight effect of suppressing tropical cyclone formation, while the SST values are neutral. The forecast also makes predictions for the number of landfalling storms in the United States and Caribbean. TSR had an strong 2011 forecast (with a near perfect prediction of ACE) , though, as their own forecast notes, “forecasts for the 2006, 2007, and 2009 hurricane seasons were less impressive”.

The United Kingdom’s Meteorological Office has been releasing outlooks since 2007, though it was only last year that they started issuing them as June-November forecasts . The forecast is derived from two global forecast models, one of their own along with one from the European Center for Medium range Weather Forecasts.

These are the forecasts that I keep track of either due to their long reputable existence or, in the case of the younger ones, notable performances. (I’ll admit I was absolutely parochial in keeping track of FSU’s model right from the start; fortunately it was a strong performer in its first two seasons). While it may seem that these are more than enough forecasts, there are yet more out there.

Everyone has a forecast

Penn State University researcher Micheal Mann has been releasing forecasts since 2007. His 2012 prediction (which comes from a statistical model) is 11 named storms.

Weatherbell Analytics is a private company that hired forecaster Joe Bastardi after he left Accuweather. Weatherbell Analytics’ 2012 hurricane season forecast is for 11 named storms, 5 hurricanes, 3 major hurricanes and 85 units of ACE. It expects fewer storms to develop far at sea and relatively more to from close in to the United States.

In the context of hurricanes, the Geophysical Fluid Dynamics Laboratory (GFDL) is best known for its specialized dynamic hurricane model. The lab has developed what it is calling a Hybrid Hurricane Forecast System for hurricane season outlooks. Unfortunately, the most recent discussion is for the January forecast run. That forecast predicted six hurricanes for the 2012 season.

Finally, the Cuban Institute of Meteorology (ISMET) has been producing forecasts since 1996. I have been unable to find an primary source document for the forecast, but a column penned by the Institute’s director, Dr. Jose Rubiera, quotes from it. Their forecast calls for ten named storms with five becoming hurricanes.

The column, originally published in Granma, the official newspaper of the Communist Party of Cuba, is actually pretty interesting. It is entitled “El Pronostico de la Temporada de Huracanes en Su Propio Lugar“, which translates to “The Hurricane Season Forecast in its Proper Place”. It discusses the purpose of hurricane season forecasts and their limitations. Rubiera outright states that the forecasts have scientific value,” but do not possess a practical value to the general public”.

I find the column valuable enough to spend time working on a translation ****, which will be the content of my next post.

*** It’s only been since 2006 that the CSU forecast explicity forecasted ACE; before then it gave only a number called Net Tropcial Cyclone (NTC) activity, which is a completely different calculation, but like ACE, does give a measure of aggregate activity. This season’s forecast NTC, 90, is the same as the 2009 forecast, but the forecast for ACE that season was 85. You have to go back to 1994, to find a NTC lower than 90. Had there been an ACE forecast, it likely would have been at 80 or lower.

**** Yes I could just run it through Google Translate or some such tool and it would probably be workable or “good enough”. Feel free to give it a whirl, yourself. I did though, get an outstanding education in the Spanish language in high school and have made use of that learning at various points since, but not recently. So I’m going to grab this surprising opportunity and run with it.

June 2, 2012

Before releasing a post summarizing the predictions for activity in the hurricane season to come, I like to review those of seasons past.

I do this to address a couple of concerns people have about these forecasts. One is that when the media reports upon them, they rarely, if ever review the performance of the forecasts in years past. The second is that the forecasts always (intentionally) over-state activity and as such exist solely to generate hype and anxiety for the forthcoming season. One lesser concern, even more conspiratorial in nature, is that the classification of tropical storms, etc is manipulated so that NOAA can “hit their numbers”.

As for second concern, 2005 remains the canonical refutation of that notion. The highest forecast for that season from the organizations tracked here was Colorado State’s, which called for 15 named storms, 8 hurricanes, and 4 major hurricanes. The actual numbers for the season were 28,15 , and 7. When you review the five hurricane seasons since, it is clear that there is not a sustained inclination to overstate activity.

A concern I won’t address in the post is the general utility of these forecasts to the average person. I expressed my thoughts in a 2007 commentary on hurricane season forecasts :”They are of little value to individuals. National Hurricane Center forecaster Richard Pasch said it best: ‘An active year is the year when you get hit.’”

With that out of the way, let us look back on the 2011 season and the pre-season predictions. The season featured 19 tropical storms, 7 hurricanes, 4 major hurricanes, and 127 units of Accumulated Cyclone Energy (ACE). The consensus numbers from the six organizations I track were 15, 8, 4, and 148.

Three of the forecasts originated from reasearchers affilitaed with universities (Colorado State, Florida State, and North Carolina State). NOAA’s forecast came from its Climate Prediction Center. Tropical Storm Risk is a British consortium, and the sixth forecast was produced by the United Kingdoms’s Meteorological Office.

Everyone under-forecast the number of tropical storms. Short-lived tropical storms such as Franklin, Gert, and Jose, brought the number of named storms above predicted levels without causing the other numbers to go over as well. All forecasts were over by one or two on the number of hurricanes, but were either on the number or were within one of the number of major hurricanes.

Most forecasts slightly to moderately overstated the amount of Accumulated Cyclone Energy. Tropical Storm Risk’s forecast was the exception as it nearly hit the number exactly.

As we’ll see below, the first two forecasts from Florida State were impressive, particularly the ACE predictions. 2011’s forecast, alas, wasn’t particularly note-worthy. Yes, it was the closest in predicting the number of tropical storms. However, that is the least important of the four numbers. ACE is the most representative number of aggregate tropical cyclone activity. The importance of the storm categories goes down with the damage potential, hence major hurricanes are most important followed by hurricanes, and then the number of tropical storms.

Here are the predictions for the past five seasons. Note that the “observed” numbers for 2007 removed Andrea and Olga due them being out of season (an adjustment I failed to make in past reviews and something that was brought to mind by Alberto and Beryl this year). Also, the UK Met Office has been releasing forecasts since 2007, but only since 2011 have they been June-November forecasts that are easily comparable to the others (past forecasts were July-November). For each year, I’ve link to NOAA’s season summaries, which provide good reviews of the atmospheric conditions that prevailed for the season and how they affected the NOAA forecasts.

In the past five years, the consensus storm numbers have been overforecasts twice (2007 and 2009) and in the ball park the other three seasons. Note that 2009 was an El Niño year. When the oscillation and its affects are not properly accounted for, over-forecasts result.

Observed

2007

2008

2009

2010

2011

ACE

72

145

51

166

127

5 season trailing avg

158

160

154

119

102

Con.

158

139

76

177

148

CSU

170

150

85

185

160

FSU

65

156

163

NOAA

147

136

85

186

140

TSR

156

131

69

182

124

UKMET

151

2007’s ACE was brutally over-forecast by everyone. With the exeption of the major hurricanes Dean and Felix, storms that season did not have long lives and therefore did not contribute much to the total. In percentage terms, the consensus forecast for 2009 was substantially overblown as well. 2011 wasn’t as bad. The consensus predictions for 2008 and 2010 were excellent

My next post will be a round-up of the forecasts for the 2012 season.

***(Note that in their forecasts as published, some organizations release ranges of numbers, or in the case of Tropical Storm Risk, numbers that aren’t whole numbers. The numbers here are averages and roundings of ranges and TSR’s numbers are rounded as well. The consensus is calculated using the unrounded numbers. That’s why the consensus numbers of major hurricanes is four, when by appearances, it should be five; TSR’s published number was 3.7 and NOAA’s range was 4-9. Those got rounded up to four and five, respectively for the purposes of the list, but the unrounded numbers were used to calculate the average of the forecasts)